| With the popularization of personal consumer electronic terminals and IoT terminals and the development of inertial navigation systems,the accuracy requirements of navigation systems are constantly improving.In some special cases,such as the paralysis of the global positioning system,the inertial navigation system will determine the overall navigation accuracy at this time.The high-precision accelerometer is an important part of the inertial navigation system.Together with the frequency source and the gyroscope,it determines the navigation accuracy.Therefore,the performance improvement of the accelerometer will promote the rapid development of inertial navigation technology.At the same time,accelerometers are also widely used in military and civil fields such as aerospace,consumer electronics,and robotics.To sum up,the research on high-precision accelerometers has important scientific value and application value.Aiming at the problems of low sensitivity and precision,weak anti-electromagnetic ability,complex manufacturing process,and difficult to integrate with CMOS circuits in existing accelerometers,this paper fabricated a variety of cavity-based optomechanical structures after indepth study and understanding of the advantages of cavity optomechanical structures.accelerometers,and performed performance test verification for one of the accelerometers.The main research contents and achievements of this paper are as follows:1.The principle of optomechanical action in the cavity optomechanical structure is analyzed,and different mechanical oscillator structures are designed based on the working principle of the cavity optomechanical structure.Finally,a single-axis straight beam structure accelerometer and three mechanical oscillators are proposed.Two-axis accelerometers with different oscillator structures are used,and the designed accelerometer structure parameters are optimized through COMSOL and FDTD simulations.For the designed accelerometer,its stability,optical and mechanical resonance characteristics,optomechanical coupling rate and sensitivity are simulated and analyzed,and the resolution and noise characteristics are theoretically analyzed.Finally,the DC sensitivity of the straight-beam accelerometer designed by simulation reaches 986.5μg/Hz,and the twoaxis DC sensitivity of the cross-beam accelerometer reaches 130.4mg/Hz respectively.and 126.58mg/Hz,the two-axis DC sensitivity of the L-beam structure accelerometer is 2.44mg/Hz and 2.56mg/Hz,inside and outside The two-axis DC sensitivity of the nested structure accelerometer is 3.14mg/Hz and 3.61mg/Hz.2.After completing the simulation design,this paper introduces and solves the problems encountered in the chip processing process,and then manufactures the single-axis straight beam accelerometer and the two-axis L-shaped accelerometer chip,and builds an experimental test platform to test and analyze the chip.The stability,optical and mechanical resonance characteristics,coupling rate,sensitivity,resolution and noise characteristics of the single-axis straight-beam accelerometer are finally obtained through experiments.The AC sensitivity of the single-axis straight-beam non-differential structure accelerometer reaches 73.99mV/g,the AC resolution is 2.1mg/（?）.3.The strip waveguide and photonic crystal waveguide with linear gradient transition region are designed by FDTD simulation.The overall transmittance reaches 60%within the band gap of photonic crystal,and the rationality of the design of the linear gradient transition region is proved.Finally,the design layout of the single-axis straight-beam accelerometer with on-chip waveguide structure is given. |
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